Hitting a target with any of Ezreal's abilities increases his attack speed by 10% for 6 seconds, this effect stacks up to 5 times.

Mystic Shot

Q

Active: Ezreal fires a bolt of energy in a line that will deal physical damage and apply on-hit effects to the first enemy it hits. If it strikes an enemy unit, all of Ezreals cooldowns will be reduced by 1 second. Range: 1100Projectile Speed: 2000

Active: Ezreal charges for 1 second to fire a powerful broad energy missile that travels in a line across the whole map and deals magic damage to each enemy unit they pass through. It will deal 10% less damage for each subsequent target hit, down to a minimum of 30% damage dealt.Cost: 100 manaCooldown: 80 secondsRange: GlobalProjectile Speed: 2000